On his way home from work, Agnus's life is turned upside down when the bus he's on is robbed. In the midst of the chaos, a mysterious masked heroine appears and hands him a book: The Hero's Handbook. With this strange guide in hand, Agnus is thrown into a hidden underworld, fragmented between heroes, villains and The Omitteds. The villains are about to join forces with The Omitteds in a rarely seen deal, as, equipped with dangerous bubble technology, they are now able to drain the virtue from almost anyone, even the heroes. With the villains' power growing, the world is on the brink of collapse. Now, Agnus will need to use the skills he acquired from the Hero's Handbook and discover that being a hero is not about power, but about wanting to.